Method for controlling crab grass and water grass



United States Patent 3,246,976 METHOD FOR CONTROLLING CRAB GRASS AND WATER GRASS Mervin E. Brokke, Richmond, and Chester L. Dewald,

Cupertino, Califi, assignors to Staufifer Chemical Company, New York, N.Y., a corporation of Delaware No Drawing. Filed June 18, 1962, Ser. No. 202,986

5 Claims. (Cl. 71--2.6)

This application is a continuation-in-part of US. application Serial No. 120,930, filed June 30, 1961, now abanwherein R is a para-halophenyl radical and R is a cyclohexyl, phenyl or a substituted phenyl radical wherein saidsubstituent is selected fromthe group consisting of'halogen, loweralkyl, lower alkoxy and mixtures thereof. By lower alkyl and alkoxy is meant such radicals containing from one to four carbon atoms.

The compounds of the present invention and the method of preparing them are old and well known in the art and thus only their use as a herbicide is held to be new and novel.

One method of preparing the compounds of the present invention is to mix an appropriately substituted benzene sulfonyl chloride with an appropriately substituted aniline in the presence of pyridine. A water solution of base, such as sodium hydroxide or the like may be substituted for the solvent pyridine as this also readily picks up the liberated HCl from the reaction and leaves the desired compound.

The compounds of the present invention have been extensively tested both as pre-emergence herbicides and post-emergence herbicides with excellent results. Preemergence herbicides are applied to a potential weed habitat either before or after seeding but before the crop emerges. If the herbicide is harmless to the desired crop, seeds or seedlings, but phytotoxic to weed seeds or seedlings encountered, the crop grows in a weed-free environment. Post-emergence herbicides are applied after the crop and/Or weeds emerge from the soil and likewise must be harmless to the desired crop and phytotoxic with respect to the weeds encountered.

The phytotoxic compositions of the present invention may be applied to the weed habitat in any of the convenient forms well known to those skilled in the art. For instance, it can be dissolved in a solvent, such as acetone, or emulsified and sprayed onto the weed habitat", or it can be combined with a dry inert carrier and applied as a dust or as granules. The rates of application may vary widely depending on the results desired.

The phytotoxicity of the compounds of the present invention is shown by the results of the following testing methods.

Example 1 Seeds of crab grass are planted in rows one-half inch deep in Santa Cruz sandy loam soil contained in compressed paper fiats 8% x 6 /2" which are 2%" deep. The flats are watered after planting and the following dayeach flat is sprayed at a rate of20 pounds of the compound under test in gallons of solution per acre. A No. 152 DeVilbiss atomizer is used to spray the solution onthe soil surface. Two weeks later the degree of weed control is determined by comparingthe amount ofgermination and growth of each weed in the treated flats with the weeds in several untreated control flats.

The following chart shows the results of the testdescribed supra.

Percent crab Compound No. R R grass control at; 20, lbs/acre 1 4-hromophenyL. 2-methylphenyl. 4-chlorophenyL. do 100 4-fluorophenyl--. do 100 These tests show excellentcontrol of hairy crab grass and since such compounds are harmless to regular lawn grasses, their utility in this manner is one embodiment ofthe presentinvention.

Example '2 This test was carried out the same as stated in Example 1 supra except that water grass was used as the weedspecies and it was grown in =8" x 12" metal flats. The soil was sprayed with a No. 152 DeVilbiss sprayer at a rate of 10 lbs. in 80 gallons of solution/ acre. The results were recorded two weeks after treatment and were as follows:

R4O NHR Pre- Opd.- No. R R emergence water grass activity 4 4-chlorophenyl. PhenyL XXX 5... d0 2-chl0rophenyl XXX 6 4-chlorophenyl XX 2-methylphenyL XXX 3-methylphenyL XX 4-methylphenyL XX 3,4-dichlorophenyl XX Cyclohexy XXX Phenyl XXX 2-chlorophenyl. XX 3-chlorophenyl X Z-methylphenyl. XXX S-methylphenyL XXX 4-methylphenyl XX 2-methoxyphenyl XXX Cyclohexyl XX Phenyl. XXX 2-chlorophenyl. XXX 3-chlorophenyL X 4-chlor0phenyL f X 3'methylphenyh XXX X indicates partial control. XX indicates good control. XXX indicates complete control.

Example 3 Seeds of water grass and rice were planted in Santa Cruz sandy loam soil contained in metal containers as in Example 2. After growing for two weeks under greenhouse conditions the plants were four to six inches tall. The foliage was then sprayed using a DeVilbiss sprayer. This spray treatment was equivalent to a rate of 10 lbs. in 80 gallons of solution/acre. Two weeks after treatment the injury results to the water grass was recorded and are reported below. The rice was unaffected by the treatment.

RS O N HR P ostem ergencc Cpd. No. R B activity on water grass 2-ethylphenyl XXX Z-methoxyphenyl XXX 4-methoxyphenyl X 2,4-dimethylphenyl- XXX 2,6-dimetl1ylphenyl XXX 2,5dimethylphenyl XXX 2-methyl-5-isopropyl- X pheny l. 2-1ncthyl-3-el1lorophenyL XX 3'chloroA-methylphenyl X 2-ethylphenyl XXX 4-methoxyphenyl X 2,4-dimethylpheny1. XX 2,6-dimethy1phenyl XX 2,5-dimethylphenyl XX Cyclohexyl XX 2ethylphenyl. XXX Z-met'noxyphenyl XXX 4-methoxyphenyl X 2,6-dimethylpheny1. XX 2,6-diethylphenyL X Cyclohexyl X 2-niethyl-3-ch1oropheny XX XXX XXX X indicates partial control. XX indicates good control. XXX indicates complete control.

We claim:

1. The method of controlling crab grass and water grass comprising applying to said grass habitat a phytotoxic amount of a compound of the formula:

wherein R is a para-halophenyl and R isa radical selected from the group consisting of cyclohexyl, phenyl, and substituted phenyl wherein said substituents are selected from the group consisting of halogen, lower alkyl and lower alkoxy.

2. The method of controlling crab grass and water grass comprising applying to said grass habitat a phytotoxic amount of 4-chlorobenzenesulfono-Z-toluidide.

3. The method of controlling crab grass and water grass comprising applying to said grass habitat a phytotoxic amount of 4-br0mobenzenesulfono-Z-toluidide.

4. The method of controlling crab grass and water grass comprising applying to said grass habitat a phytotoxic amount of 4-chlorobenzenesulfono-2-ethylanilide.

5. The method of controlling crab grass and water grass comprising applying to said grass habitat a phytotoxic amount of N-cyclohexyl-4-chlorobenzenesulionamide.

References Cited by the Examiner UNITED STATES PATENTS 1,955,207 4/1934 Stotter et a1. 260556 1,962,276 6/1934 Huismann et al. 260-556 2,964,538 12/1960 Kundiger et al 712.6 X 3,046,104 7/1962 Ehlers et al. 712.3

FOREIGN PATENTS 823,970 12/ 1957 Germany.

OTHER REFERENCES Fromm et al,, Chemical'Abstracts, vol. 46, 1952, 71-

2.3, col. 8315g.

Nultsch et al., German'application 1,091,419, printed Oct. 20, 1960, Kl. 53C 6/01. (2 pp. spec., no clwg.)

LEWIS GOTTS, Primary Examiner. V IRVING MARCUS, JULIAN S. LEVITT, Examiners. 

1. THE METHOD OF CONTROLLING CRAB GRASS AND WATER GRASS COMPRISING APPLYING TO SAID GRASS HABITAT A PHYTOTOXIC AMOUNT OF A COMPOUND OF THE FORMULA: 